3D printers have opened up all kinds of possibilities when it comes to turning digital blueprints into real word objects, but might they also enable new ways to pilfer intellectual property? Amid all that mechanical whirring, these machines emit acoustic signals that give away the motion of the nozzle, new research has found. And by discreetly recording these sounds, scientists say it is possible for sneaky characters to deduce design details and reverse engineer printed objects at a later date.

While the source code for 3D printed designs can be guarded through encryption and regular means, once the machine is swung into action that sensitive information may be compromised, researchers at the University of California Irvine (UCI) have discovered.

Led by Mohammad Al Faruque, director of the Advanced Integrated Cyber-Physical Systems lab, the team found that placing a smartphone alongside the machine as it printed objects layer-by-layer enabled them to capture the acoustic signals. It says that these recordings contain information about the precise movement of the nozzle, and that information can later be used to reverse engineer the item being printed.

Using this technique, Al Faruque and his team were able to reproduce a key-shaped object with almost 90 percent accuracy.

"In many manufacturing plants, people who work on a shift basis don't get monitored for their smartphones, for example," he says. "If process and product information is stolen during the prototyping phases, companies stand to incur large financial losses. There's no way to protect these systems from such an attack today, but possibly there will be in the future."

One of the possible ways engineers could stonewall would-be thieves might be to confuse the acoustic signals through additional white noise, Al Faruque says. His discovery has attracted interest from other researchers at UCI and at various government agencies. The team are preparing to present their findings at the International Conference on Cyber-Physical Systems in Vienna in April.